P.0304 Circulating insulin levels and serotonin transporter expression in obese subjects

The gastric peptide ghrelin promotes energy storage, appetite, and food intake. Nutrient intake strongly suppresses circulating ghrelin via molecular mechanisms possibly involving insulin and gastrointestinal hormones. On the basis of the growing evidence that glucose-dependent insulinotropic polypeptide (GIP) is involved in the control of fuel metabolism, we hypothesized that GIP and/or insulin, directly or via changes in plasma metabolites, might affect circulating ghrelin. Fourteen obese subjects were infused with GIP (2.0 pmol·kg−1·min−1) or placebo in the fasting state during either euglycemic hyperinsulinemic (EC) or hyperglycemic hyperinsulinemic clamps (HC). Apart from analysis of plasma ghrelin and insulin levels, GC-TOF/MS analysis was applied to create a hormone-metabolite network for each experiment. The GIP and insulin effects on circulating ghrelin were analyzed within the framework of those networks. In the HC, ghrelin levels decreased in the absence (19.2% vs. baseline, P = 0.028) as well as in the presence of GIP (33.8%, P = 0.018). Ghrelin levels were significantly lower during HC with GIP than with placebo, despite insulin levels not differing significantly. In the GIP network combining data on GIP-infusion, EC+GIP and HC+GIP experiments, ghrelin was integrated into hormone-metabolite networks through a connection to a group of long-chain fatty acids. In contrast, ghrelin was excluded from the network of experiments without GIP. GIP decreased circulating ghrelin and might have affected the ghrelin system via modification of long-chain fatty acid pools. These observations were independent of insulin and offer potential mechanistic underpinnings for the involvement of GIP in systemic control of energy metabolism.

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Chronic restraint stress induces serotonin transporter expression in the rat adrenal glands

Molecular and Cellular Endocrinology ◽

10.1016/j.mce.2020.110935 ◽

2020 ◽

Vol 518 ◽

pp. 110935

Author(s):

Shiv Shanker ◽

Neeshu Saroj ◽

Emilio J. Cordova ◽

Rosa A. Jarillo-Luna ◽

Pedro López-Sánchez ◽

...

Keyword(s):

Serotonin Transporter ◽

Restraint Stress ◽

Adrenal Glands ◽

Chronic Restraint Stress ◽

Transporter Expression

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Increased Serotonin Transporter Expression Reduces Fear and Recruitment of Parvalbumin Interneurons of the Amygdala

Neuropsychopharmacology ◽

10.1038/npp.2015.157 ◽

2015 ◽

Vol 40 (13) ◽

pp. 3015-3026 ◽

Cited By ~ 21

Author(s):

Marco Bocchio ◽

Giulia Fucsina ◽

Lydia Oikonomidis ◽

Stephen B McHugh ◽

David M Bannerman ◽

...

Keyword(s):

Serotonin Transporter ◽

Parvalbumin Interneurons ◽

Transporter Expression

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Psychostimulants Differentially Regulate Serotonin Transporter Expression in Thalamocortical Neurons

Journal of Neuroscience ◽

10.1523/jneurosci.22-01-j0003.2002 ◽

2002 ◽

Vol 22 (1) ◽

pp. RC192-RC192 ◽

Cited By ~ 28

Author(s):

Terri L. Whitworth ◽

Laura C. Herndon ◽

Michael W. Quick

Keyword(s):

Serotonin Transporter ◽

Transporter Expression

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Fasting Ghrelin Levels Are Decreased in Obese Subjects and Are Significantly Related With Insulin Resistance and Body Mass Index

Open Access Macedonian Journal of Medical Sciences ◽

10.3889/oamjms.2017.182 ◽

2017 ◽

Vol 5 (6) ◽

pp. 699-702 ◽

Cited By ~ 3

Author(s):

Dimitrios Papandreou ◽

Christos Karavolias ◽

Fotini Arvaniti ◽

Eleana Kafeza ◽

Fatima Sidawi

Keyword(s):

Insulin Resistance ◽

Body Mass Index ◽

Body Mass ◽

Insulin Levels ◽

Amino Acid Peptide ◽

Glucose Levels ◽

Metabolic Functions ◽

Fasting Plasma ◽

Overnight Fasting ◽

Obese Subjects

BACKGROUND: Ghrelin is a 28-amino acid peptide that predominantly produced by the stomach. Strong evidence indicates the effects of ghrelin in the regulation of metabolic functions and its potential role in the aetiology of obesity.AIM: The aim of this study was to investigate the relationship of ghrelin levels with obesity, insulin resistance and glucose in normal and obese subjects.METHODS: Thirteen normal (n = 13) and seven (n = 7) obese weight subjects aged 20-22 participated in the study. Fasting plasma ghrelin, insulin and glucose levels were measured after overnight fasting. HOMA-IR was calculated to evaluate insulin resistance.RESULTS: Ghrelin and insulin levels were found to be statistically significantly lower and higher in obese subjects (P < 0.001), respectively. Glucose levels were clinically higher in obese subjects but not statistically significant. Fasting plasma ghrelin was negatively correlated with BMI (r = -0.77, P < 0.001), fasting insulin levels (r = -0.55, P < 0.001) and HOMA-IR (r = -0.66, P < 0.001). There was no correlation between ghrelin and glucose. In multiple regression analysis, insulin levels (Beta: -2.66, 95% CI: -2.49, -2.78, P < 0.001) HOMA-IR (Beta: -2.41, 95% CI: -2.33, -2.55, P < 0.001) and BMI (Beta: -1.77, 95% CI: -1.66, -1.89, P < 0.001) were significant independent determinants of fasting ghrelin.CONCLUSION: Obese subjects have low fasting ghrelin levels that they are significantly related to insulin resistance and body mass index. More prospective studies are needed to establish the role of ghrelin in the pathogenesis of human obesity.

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